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Oxytocin & the Biochemical Effects of Betrayal

biochemicalInvestigators have discovered the neurophysiological basis of human trust and the reaction to it being breached.

In the study, scientists were able to prove the hormone oxytocin plays a vital role toward the sentiment of trust, even after a betrayal.

The ability of human beings to live in societies is based on trust. Whether in love or politics, in family or business life, trust always plays an important role. The interest was correspondingly high when researchers at the University of Zurich discovered three years ago that oxytocin promotes a feeling of trust.

However, the neurophysiological basis of that effect and why oxytocin increases trust remained unknown.

Another unanswered question was whether oxytocin can influence the behavior of trust, even after one person’s faith in another has been betrayed.

A research team at the University of Zurich with the neuroscientist Thomas Baumgartner, the neuroeconomist Ernst Fehr, and the psychologist Markus Heinrichs has now determined that oxytocin exerts an influence on how human beings deal with a breach of trust.

Test subjects who received a placebo reacted to a betrayal of trust by a reduction in their level of trust. On the other hand, people who received oxytocin by means of a nasal spray did not change their trusting behavior.

This differing reaction to a breach of trust is associated with a very specific activation pattern in the brain. Test subjects who received oxytocin demonstrated a lower activation in the amygdala, in regions of the midbrain and in the dorsal nucleus of the caudatus.

This pattern indicates that oxytocin reduces the activation in those structures of the brain which are involved not only in dealing with fear but also in the adaptation of behaviour following a negative experience such as a betrayal of trust.

These new findings could help in gaining more profound knowledge of mental disorders in which a social deficit is at the forefront. As explained by the psychologist Markus Heinrichs, clinical studies are being examined in which an intranasal administration of oxytocin is combined with standardized behavioral therapy in the treatment of disorders such as social phobia and borderline personality dysfunction.

In the brain, oxytocin appears to primarily be a chemical messenger, and has been found to be important factor in human behaviors including sexual arousal, recognition, trust, and anxiety. As a result, oxytocin has been called the ‘love hormone.’ It is also a key hormone for childbirth and lactation.

The neuroscientist Thomas Baumgartner hopes that the results will lead to fertile research into mental disorders of that kind. Particularly the knowledge about where in the brain the effect of oxytocin manifests itself could help in the development of even better therapeutic measures.

The neuroeconomist Ernst Fehr adds: “We have discovered significant elements of the neural basis of trust after a betrayal of trust has taken place. In view of the importance of trust in human social interaction, these results open up the possibility of being able to fathom and increase our general understanding of the neurophysiological basis of prosocial behavior.”

The limitations of this study were that it was conducted on a small sample size. The research would need to be replicated on a larger, more diverse sample size to ensure that the researchers’ findings can be more generalized.

Source: University of Zurich

Oxytocin & the Biochemical Effects of Betrayal

This article has been updated from the original version, which was originally published here on May 23, 2008.

Rick Nauert PhD

Rick Nauert, PhDDr. Rick Nauert has over 25 years experience in clinical, administrative and academic healthcare. He is currently an associate professor for Rocky Mountain University of Health Professionals doctoral program in health promotion and wellness. Dr. Nauert began his career as a clinical physical therapist and served as a regional manager for a publicly traded multidisciplinary rehabilitation agency for 12 years. He has masters degrees in health-fitness management and healthcare administration and a doctoral degree from The University of Texas at Austin focused on health care informatics, health administration, health education and health policy. His research efforts included the area of telehealth with a specialty in disease management.

APA Reference
Nauert PhD, R. (2019). Oxytocin & the Biochemical Effects of Betrayal. Psych Central. Retrieved on October 1, 2020, from
Scientifically Reviewed
Last updated: 3 May 2019 (Originally: 23 May 2017)
Last reviewed: By a member of our scientific advisory board on 3 May 2019
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